Deploying Radiant to Heroku in 5 minutes causes permissions error in Admin

I put these two tutorials together..

Radiant on Heroku in 5 minutes

Using Bundler with 2.3.5

and in my Gemfile, I also included :

gem "taps"
gem "radiant"

And when I run Radiant on my local, no problem! I can access the Admin.

When I run it on Heroku, the frontpage works, but the admin gives me a :

Application error

Change this error message for exceptions thrown outside of an action (like in Dispatcher setups or broken Ruby code) in public/500.html

I checked the logs and they say;

Rendering admin/welcome/login

ActionView::TemplateError (Permission denied - /disk1/home/slugs/6d4358ef-a4c2-411e-b46d-e6224d3c36fb/mnt/public/javascripts/admin/all.js) on line #9 of /home/slugs/6d4358ef-a4c2-411e-b46d-e6224d3c36fb/mnt/.bundle/gems/ruby/1.8/gems/radiant-0.9.1/app/views/layouts/application.html.haml:
6:     - @stylesheets.uniq.each do |stylesheet|
7:       = stylesheet_link_tag stylesheet
8:     %script{:type=>"text/javascript"}="var relative_url_root = '#{ActionController::Base.relative_url_root}';"
9:     = javascript_include_tag %w(admin/prototype admin/effects admin/lowpro admin/dateinput admin/pagestatus admin/cookie admin/popup admin/status admin/utility admin/codearea admin/tabcontrol admin/ruledtable admin/sitemap admin/shortcuts admin/toggle admin/validationerror admin/application), :cache => 'admin/all'
10:     - @javascripts.uniq.each do |javascript|
11:       = javascript_include_tag javascript
12:     - if @content_for_page_scripts

    radiant (0.9.1) app/views/layouts/application.html.haml:9:in `_run_haml_47home47slugs476d4358ef45a4c245411e45b46d45e6224d3c36fb47mnt4746bundle47gems47ruby47146847gems47radiant45046946147app47views47layouts47application46html46haml'
    radiant (0.9.1) vendor/plugins/haml/rails/./lib/haml/helpers/action_view_mods.rb:13:in `render'
    radiant (0.9.1) vendor/plugins/haml/rails/./lib/haml/helpers/action_view_mods.rb:13:in `render'
    radiant (0.9.1) vendor/plugins/haml/rails/./lib/sass/plugin/rails.rb:20:in `process'
    /home/heroku_rack/lib/stati开发者_高级运维c_assets.rb:9:in `call'
    /home/heroku_rack/lib/last_access.rb:15:in `call'
    /home/heroku_rack/lib/date_header.rb:14:in `call'
    thin (1.2.6) lib/thin/connection.rb:76:in `pre_process'
    thin (1.2.6) lib/thin/connection.rb:74:in `catch'
    thin (1.2.6) lib/thin/connection.rb:74:in `pre_process'
    thin (1.2.6) lib/thin/connection.rb:57:in `process'
    thin (1.2.6) lib/thin/connection.rb:42:in `receive_data'
    eventmachine (0.12.10) lib/eventmachine.rb:256:in `run_machine'
    eventmachine (0.12.10) lib/eventmachine.rb:256:in `run'
    thin (1.2.6) lib/thin/backends/base.rb:57:in `start'
    thin (1.2.6) lib/thin/server.rb:156:in `start'
    thin (1.2.6) lib/thin/controllers/controller.rb:80:in `start'
    thin (1.2.6) lib/thin/runner.rb:177:in `send'
    thin (1.2.6) lib/thin/runner.rb:177:in `run_command'
    thin (1.2.6) lib/thin/runner.rb:143:in `run!'
    thin (1.2.6) bin/thin:6
    /usr/ruby1.8.7/bin/thin:19:in `load'
    /usr/ruby1.8.7/bin/thin:19

Rendering /disk1/home/slugs/6d4358ef-a4c2-411e-b46d-e6224d3c36fb/mnt/public/500.html (500 Internal Server Error)

In order to solve this, I created the files that it was looking to make on my local.

script/server -e production

Then I logged into: http://localhost:3000/admin/

After that the pages became created, and I performed

git add .
git commit -m "created temp admin files for production"
git push heroku master

It's the :cache => 'admin/all' in your JavaScript link tag that's causing it, because on Heroku you only have write permissions for ./tmp and ./log.